Earlier today I was asked to join the Habari project management committee, and I enthusiastically said, "yes!" I've been putting in a lot of hours lately into implementing Habari's new user interface, named Monolith by Michael Heilemann. I am very excited about this platform and where it is headed. The community of people around the project have been very welcoming and supportive of my work. So, thanks!

@Terri:
There are several answers to that question. First of all, from a backend perspective, Habari was started at least half a decade after Wordpress. Web programming technologies have come a long way since then, so Habari gets to start with all the latest tools available, such as object-oriented programming, model-view-controller structure, prepared SQL statements, etc. This means that Habari started with a view toward extensibility and security, whereas these things were kind of tacked on to Wordpress.

Another aspect is user interface design. The Wordpress developers have become attached to certain aspects of their administrative interface, and have been very slow to accept changes. Wordpress 2.5 made strides in the right direction, but I still think that the WP administrative interface is still cluttered, commonly used features are too many clicks away, and in general, it does not adequately focus on the most important aspect of all blogging platforms: writing. In this respect, I think Habari is leagues beyond any other blogging software currently available.

The last thing is about the community around the project. Wordpress is open source software, but it is controlled by the Automattic corporation. Automattic and Wordpress have a mixed history in their ability to accept and support the efforts of dedicated developers within their community. Frankly, I think the spirit of innovation has largely evaporated, or at least, the innovation is focused more on Wordpress.com than it is on Wordpress.org. Habari has captured that spirit of change, and is rapidly incorporating ideas from its community of developers. Habari is founded around the meritocratic model, so there is no one person making decisions for the entire community. This should enable Habari to make quick progress in becoming one of the best blogging tools available.